1. Field of the Invention
This invention generally relates to a laser device, a control device of a laser device, a method of controlling a laser device, a method of tuning a wavelength of a laser device and a control data of a laser device.
2. Description of the Related Art
Recently, an information-processing device and so on using a semiconductor laser have been developed. There is a demand for a high quality property such as tunability or stability of wavelength. And so, “Broad-Band Tunable Two-Section Laser Diode with External Grating Feedback” (IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 2, NO. 2, FEBRUARY 1990, PP. 85-87) discloses a wavelength tunable laser that has a wavelength-tuning portion controlling a transmission wavelength in an external cavity system. The wavelength tunable laser reflects a light of a given wavelength to a gain media (laser diode) by using a grating. The lasing wavelength is thus tunable.
However, it is necessary that the wavelength tunable laser controls the wavelength-tuning portion optimally, in order for a desirable lasing oscillation.